Question

A square shaped plane coil of area $100c{m}^2$ turns carries a steady current of 5A. it is placed in a uniform magnetic filed of 0.2 T acting perpendicular to the plane of the coil. Calculate the torque on the coil when its plane makes an angle of ${60}^o$ with the direction of the field. In which oscillation will the coil be in stable equilibrium?

Answer 1

$A=100c{m}^2={10}^{-2}{m}^2$

$N=200turns,I=5A,B=0.2T$

$\theta ={90}^o-{60}^o$

$\tau =NIABsin\theta$

$\tau =200\times 5\times {10}^{-2}\times sin{30}^o=1Nm$

The coil will be in stable equilibrium when it is parallel to the magnetic field.